User interface for controlling light emitting diodes

ABSTRACT

A LED lighting system ( 100 ) employing a LED light source ( 115 ), a user interface ( 124, 128, 134, 138 ), and a controller ( 112 ). The LED light source ( 115 ) includes a plurality of colored LEDs emitting one of a plurality of spectral outputs as a function of one or more currents flowing through the colored LEDs, where each current has a variable time average flow. The user interface ( 124, 128, 134, 138 ) facilitate a user selection of one of the spectral outputs. The controller ( 112 ) controls the variable time average flow of each current flowing through the colored LEDs as a function of the spectral output selected by the user.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. provisional application Ser.No. 60/468,552, filed May 7, 2003, which the entire subject matter isincorporated herein by reference.

In general, the present invention relates to light-emitting diode(“LED”) light sources. More specifically, the present invention relatesto user interfaces for facilitating user control of a spectral output ofa LED light source.

Most artificial light is produced by an electric discharge through a gasin a lamp. One such lamp is the fluorescent lamp. Another method ofcreating artificial light includes the use of a LED, which provides aspectral output in the form of a radiant flux that is proportional to aforward current flowing through the LED. Additionally, a LED lightsource can be used for generation of a multi-spectral light output.

Conventional LED light sources utilize individual encapsulated lightemitting diodes or groups of light emitting diodes of substantiallysimilar spectral characteristics encapsulated as a unit. Typically,conventional LED light sources are implemented as color converted LEDlight sources. Color corrected LED light sources are manufactured byapplying a phosphor compound layer to a LED, either directly or withinan encapsulent. The phosphor layer absorbs the light emitted by the LEDor a portion of the light emitted by the LED and emits light based on aninteraction of the absorbed light and the phosphor compound. The colorcorrected LED light sources are grouped together to form the LED lightsource. Color corrected LEDs realize maximum accuracy in spectral outputwhen a specified amount of direct current is applied to the colorcorrected LEDs. The specified amount of direct current, among otherdata, is included in a rating for each color corrected LED.

It is a difficult problem to combine and maintain correct proportions oflight from multi-colored LEDs to create light that is of desired colorand intensity as well as reasonable spatial uniformity, because LEDspectra and efficiencies change with current, temperature and time. Inaddition, LED properties vary from LED to LED, even from a singlemanufacturing batch. As LED manufacturing improves with time, LED-to-LEDvariations may become smaller, but LED variations with temperature,current, and time are fundamental to the semiconductor devices.Historically, conventional control systems adjust intensity levels ofspectral output by increasing or decreasing the number of LEDs receivingthe specified amount of direct current. There are several disadvantagesassociated with this type of direct current regulation, such as, forexample inaccuracy of a desired spectral output.

The present invention overcomes these drawbacks of the prior art with anew and unique touch screen-interface for facilitating user control of aspectral output and an intensity of a LED light source with a greaterdegree of accuracy than the prior art.

One form of the present invention is a LED lighting system employing aLED light source, a user interface, and a controller. The LED lightsource includes a plurality of colored LEDs emitting one of a pluralityof spectral outputs as a function of one or more currents flowingthrough the colored LEDs, where each current has a variable time averageflow. The user interface facilitates a user selection of one of thespectral outputs. The controller controls the variable time average flowof each current flowing through the colored LEDs as a function of thespectral output selected by the user.

The foregoing form and other features and advantages of the inventionwill become further apparent from the following detailed description ofthe presently preferred embodiment, read in conjunction with theaccompanying drawings. The detailed description and drawings are merelyillustrative of the invention rather than limiting, the scope of theinvention being defined by the appended claims and equivalents thereof.

FIG. 1 illustrates one embodiment of a LED lighting system forcontrolling a spectral output of a LED light source in accordance withthe present invention;

FIG. 2 illustrates a first embodiment in accordance with the presentinvention of the LED lighting system illustrated in FIG. 1;

FIG. 3 illustrates a second embodiment in accordance with the presentinvention of the LED lighting system illustrated in FIG. 1;

FIG. 4 illustrates a third embodiment in accordance with the presentinvention of the LED lighting system illustrated in FIG. 1; and

FIG. 5 illustrates one embodiment of a graphical user interface forcontrolling a spectral output of a LED light source in accordance withthe present invention.

A lighting system 100 as illustrated in FIG. 1 includes a LED lightsource 110, a computer 120, and a portable computer 130. Lighting system100 controls a spectral output of LED light source 110. Lighting system100 may include additional components not relevant to the presentdiscussion.

LED light source 110 includes a LED light source controller 112, and aconventional color LED lamp 115. LED light source controller 112 iscapable of receiving/recognizing a control signal of any type fromdevices 120 and 130. As will be explained in further detailed inconnection with FIG. 5, LED light source controller 112 is designed toreceive the control signal from either device 120 or 130, and to provideone or more direct currents via an interface (e.g., a RS-232 serialinterface) to LED lamp 115 based on the received control signal.

In one embodiment, LED light source controller 112 includes a powersource. In this embodiment, LED light source controller 112 receives thecontrol signal and provides direct current(s) to LED lamp 115 based onthe received control signal. In another embodiment, LED light sourcecontroller 112 excludes a power source. In this embodiment, LED lightsource controller 112 receives a power control signal and providesdirect currents to LED lamp 115 based on the received power controlsignal.

In another embodiment, LED light source controller 112 includes hardwareand software enabling LED light source controller 112 to receive awireless control signal. In this embodiment, LED light source controller112 includes a power source. LED light source controller 112 receivesthe wireless control signal and provides direct current to LED lamp 115based on the received wireless control signal.

LED lamp 115 represents one or more direct current driven light sources.Each LED lamp within LED lamp 115 includes a plurality of colored LEDs.In one embodiment, each LED lamp within LED lamp 115 includes aplurality of LEDs representing the colors red (R), green (G), and blue(B). In another embodiment, each LED lamp within LED lamp 115 includes aplurality of LEDs representing two of the colors red (R), green (G), orblue (B). The LEDs may be implemented in any suitable form, such as, forexample color converted LEDs or direct emitting LEDs. In yet anotherembodiment, each LED lamp within LED lamp 115 includes a plurality ofLEDs representing the colors red (R), green (G), blue (B), and amber(A).

Computer 120 includes a processor 121, an input device 122, and a userinterface in the form of a graphical user interface 123 and atouch-screen 124. Computer 120 can be implemented as any suitablecomputer, such as, for example a personal computer so long as itincludes graphical user interface 123 and touch screen 124. Processor121 includes a processor (not shown) designed to receive data, processthe received data, and produce a control signal based on the processeddata. Processor 121 additionally includes a data interface designed tomodify the control signal into a suitable format for communicationoperations, such as a wired data transfer as represented by the solidarrow extending from device 120 to source 110 or a wireless datatransfer as represented by the dashed arrow extending from device 120 tosource 110. Processor 121 receives user inputs from graphical userinterface 123 and touch screen 124. In one embodiment, a user of system100 communicates a desired spectral output to processor 121 utilizinggraphical user interface 123 and touch screen 124. Touch screen 124 canbe implemented as any suitable touch screen, such as, for example aresistive touch screen or a capacitive touch screen.

Portable computer 130 includes a processor 131, an input device 132, anda user interface in the form of a graphical user interface 133 and touchscreen 134. Computer 130 can be implemented as any suitable computer,such as, for example a personal data assistant, tablet PC, notebook PC,so long as it includes a graphical user interface 133, a touch-screen134, and a wireless capability compatible with LED light sourcecontroller 112 as well as computer 120. In one embodiment, processor 131includes a processor designed to receive data, process the receiveddata, and produce a data signal based on the processed data to betransmitted to computer 120. In another embodiment, processor 131includes a processor designed to receive data, process the receiveddata, and produce a control signal based on the processed data to betransmitted to LED light source controller 112. Processor 131 receivesuser input from graphical user interface 133 and touch screen 134. Inone embodiment, a user of system 100 communicates spectral output andintensity information to processor 131 utilizing graphical userinterface 133 and touch screen 134. Touch screen 134 can be implementedas any suitable touch screen, such as, for example a resistive touchscreen or a capacitive touch screen.

FIG. 2 is a block diagram illustrating a system 200 for controlling aspectral output emitted from a LED light source. System 200 includes acontroller 210, a user interface 220, a wireless color LED light source230, and a wired LED light source 235. System 200 may include additionalcomponents not relevant to the present discussion.

Controller 210 includes a processor 215 and a data interface 217. Userinterface 220 is operably coupled to controller 210 and in communicationwith processor 215. In one embodiment, wireless color LED light source230 is in wireless communication with controller 210 and incommunication with data interface 217 as well. In another embodiment,wired LED light source 235 is operably coupled to controller 210 and incommunication with data interface 217.

In operation, controller 210 receives user selections of spectraloutputs via user interface 220 via a wired transmission. Processor 215receives the user selections, processes the received user selections,and produces a control signal based on the processed user selection.Processor 215 sends the control signal to data interface 217 fortransmission to one or both color LED light sources 230 and 235. In oneembodiment, data interface 217 modifies the control signal into asuitable format for communication via wired data transfer. In anotherembodiment, data interface 217 modifies the control signal into asuitable format for communication via wireless data transfer. In anexample and referring to FIG. 1 above, system 200 represents interactionbetween computer 120 LED and light source 110 based on user selectionsvia graphical user interface 123 and touch screen 124 of computer 120.

FIG. 3 is a block diagram illustrating a system 300 for controlling aspectral output emitted from a LED light source. System 300 includes acontroller 310, a user interface 320, a wireless color LED light source330, and a wired LED light source 335. System 300 may include additionalcomponents not relevant to the present discussion.

Controller 310 includes a processor 315 and a data interface 317. Userinterface 320 is operably coupled to controller 310 and in communicationwith processor 315. In one embodiment, wireless color LED light source330 is in wireless communication with controller 310 and incommunication with data interface 317 as well. In another embodiment,wired LED light source 335 is operably coupled to controller 310 and incommunication with data interface 317.

In operation, controller 310 receives user selections of spectraloutputs via user interface 320 via a wireless transmission. Processor315 receives the user selections, processes the received userselections, and produces a control signal based on the processed userselection. Processor 315 sends the control signal to data interface 317for transmission to one or both color LED light sources 330 and 335. Inone embodiment, data interface 317 modifies the control signal into asuitable format for communication via wired data transfer. In anotherembodiment, data interface 317 modifies the control signal into asuitable format for communication via wireless data transfer. In anexample and referring to FIG. 1 above, system 300 represents interactionbetween computer 130 and light source 110 based on user selections viagraphical user interface 133 and touch screen 134 of computer 130.

FIG. 4 is a block diagram illustrating a system for controlling spectraloutput emitted from a LED light source. System 400 includes controller410 and LED light source 450. System 400 may include additionalcomponents not relevant to the present discussion Controller 410 is inwireless communication with LED light source 450. Controller 410includes user interface 420 and mobile processor 415. LED light source450 includes data interface 417 and color LEDs 430. User interface 420is coupled to mobile processor 415. Mobile processor 415 is incommunication with data interface 417. Data interface 417 is incommunication with color LEDs 430.

In operation, mobile processor 415 receives user selections of spectraloutputs from user interface 420. Mobile processor 415 receives the userselections, processes the received user selections, and produces a datasignal based on the processed user selections. Controller 410 providesthe data signal to data interface 417, within 450, for transmission tocolored LEDs 430. Data interface 417 produces a control signal based onthe data signal received from controller 410. In an example andreferring to FIG. 1 above, system 400 represents interaction betweenportable computer 130 and LED light source 110 based on user selectionsprovided to graphical user interface 133 and touch screen 134 ofportable computer 130.

FIG. 5 is a diagram illustrating a graphical user interface 500 forcontrolling a spectral output emitted from a LED light source. Graphicalinterface 500 is a software component that includes a chromaticitydiagram 510, a color temperature scale 520, and an intensity scale 530.Graphical interface 500 additionally includes preset color temperaturebuttons 541-546. Chromaticity diagram 510 includes a Planckian locus511, a white light area 512, and color areas 513-518. Color temperaturescale 520 includes a slider bar 525. Intensity scale 530 additionallyincludes a slider bar 535.

Graphical interface 500 is a graphical representation that allows a userto select a spectral output a LED lighting source. Chromaticity diagram510 is a graphical representation of International Commission onIllumination (“CIE”) Standard Observer. In one embodiment, chromaticitydiagram 510 is a graphical representation of a Maxwell's triangleuniform color scale (“UCS”). In other embodiments, chromaticity diagram510 is a graphical representation of a 1960 CIE UCS or a 1976 CIE UCS.Planckian locus 511 defines locations of “white” within chromaticitydiagram 510. White light area 512 is an area closely surroundingPlanckian locus 511 having an appearance of “white” to the unaided eye.

Color areas 513-515 are areas defining primary color areas having anappearance of blue (B) 513, red (R) 514, and green (G) 515 to theunaided eye. Color areas 516-518 are areas defining color change betweena set of primary colors. Color area 516 is an area defining color changebetween blue (B) 513 and red (R) 514. Color area 517 is an area definingcolor change between blue (B) 513 and green (G) 515. Color area 518 isan area defining color change between red (R) 514 and green (G) 515.

Color temperature scale 520 is a color temperature scale that allowsadjusting of a color point of white light along locus 511 utilizingslider bar 525. In one embodiment, color temperature scale 520 includesa temperature scale with a range from 2000 degrees Kelvin to 10,000degrees Kelvin.

Intensity scale 530 is an intensity scale that allows adjusting of adimming level utilizing slider bar 535. In one embodiment, intensityscale 530 includes an intensity scale with a range of percentages from 0percent (no light output) to 100 percent (maximum light output). In anexample, intensity scale 530 of graphical user interface 500 allows auser to adjust dimming level within a defined physical area or location,such as, for example a living room, a conference room, and the like.

Preset color temperature buttons 541-546 are preprogrammed locationswithin graphical user interface 500 that allow a specific colortemperature to be accessed. In one embodiment, preset color temperaturebuttons 541-543 are preprogrammed locations within graphical userinterface 500 that are preprogrammed by a manufacturer or designer to aset of specific color temperatures. In one example, preset colortemperature button 541 is preprogrammed by a manufacturer or designer tothe center of Planckian locus 511 and has an appearance of “white” tothe unaided eye. In this embodiment, preset color temperature buttons544-546 are programmed locations within graphical user interface 500that are programmed by a user to a set of specific color temperatures.

Graphical user interface 500 is designed to receive user selection ofspectral output(s). In one embodiment, graphical user interface 500receives a user provided spectral output that identifies a locationwithin chromaticity diagram 510, called a color point, and a locationwithin intensity scale 530. Graphical user interface 500 provides colorpoint data and intensity values to a processor for processing into acontrol signal that provides a user desired spectral output. The colorpoint data is expressed as an x-coordinate and a y-coordinate withinchromaticity diagram 510. The intensity value is expressed as a dimminglevel percentage within intensity scale 530. The processor may utilizeany number of conventional methods for determining a predefined ratio ofred (R), green (G), and blue (B) output necessary to match the userdesired spectral output. In one embodiment, the ratio of red (R), green(G), and blue (B) output necessary to match the user desired spectraloutput is expressed in units of lumens. Once the ratio of red (R), green(G), and blue (B) output is determined, the output is scaled based onthe intensity value. The resultant scaled output includes data necessaryto produce the user desired spectral output and intensity. In oneembodiment, the processor produces a control signal based on the scaledoutput data. In an example, the processor produces a control signalbased on the scaled output data that scales direct current delivered toindividual or groups of color light emitting diodes (LEDs), such as, forexample direct emitting LEDs.

In summary, the current regulation of the present invention is based onvarying the time average flow of current(s) (e.g, a DC level current orpulse width modulated current) through the colored LEDs to achieve adesired spectral output as opposed to a conventional regulation ofproviding a specified flow level of current to some or all of thecolored LEDs to obtain the desired spectral output.

The above-described systems for controlling the spectral output of a LEDlight source are example implementations of the present invention. Theseexemplary implementations illustrate various possible approaches forcontrolling spectral output of a LED light source. The actualimplementation may vary from the system discussed. For example,additional colored LEDs (e.g., amber) may be employed within a LED lightsource whereby diagram 510 would be having four or more sides. Moreover,various other improvements and modifications to the present inventionmay occur to those skilled in the art, and those improvements andmodifications will fall within the scope of the present invention as setforth in the claims below.

The present invention may be embodied in other specific forms withoutdeparting from its essential characteristics. The described embodimentsare to be considered in all respects only as illustrative and notrestrictive.

1. A LED lighting system, comprising: a LED light source including aplurality of colored LEDs operable to emit one of a plurality ofspectral outputs as a function of at least one current flowing throughsaid plurality of colored LEDs, each current of the at least one currenthaving a variable time average flow; a user interface operable tofacilitate a first user selection of a first spectral output from theplurality of spectral outputs; and a controller in electricalcommunication with said user interface and said LED light source tocontrol the variable time average flow of each current flowing throughsaid plurality of colored LEDs as a function of the first spectraloutput, wherein said user interface includes: a graphical user interfaceoperable to display a chromaticity diagram encompassing a plurality ofcolor points, each color point corresponding to one of the plurality ofspectral outputs; and a touch screen operable to facilitate the firstuser selection of a first color point corresponding to the firstspectral output.
 2. The LED lighting system of claim 1, wherein thecontroller is in wireless communication with the LED light source. 3.The LED lighting system of claim 1, wherein said graphical userinterface is further operable to display a color temperature scaleincluding a slider bar for adjusting a color temperature of the firstspectral output.
 4. The LED lighting system of claim 1, wherein saidgraphical user interface is further operable to display an intensityscale encompassing a plurality of intensity levels for the first colorpoint; and wherein said touch screen is further operable to facilitate asecond user selection of a first intensity level for the first colorpoint.
 5. The LED lighting system of claim 4, wherein said controller isfurther operable to scale the variable time average flow of each currentas a function of the second user selection of the first intensity level.6. The LED lighting system of claim 1, wherein the plurality of coloredLEDs includes LEDs having at least four different colors.
 7. The LEDlighting system of claim 6, wherein the at least four colors includered, green, blue, and amber.
 8. The LED lighting system of claim 1,wherein the controller is in wireless communication with the userinterface.
 9. The LED lighting system of claim 8, wherein the controlleris in wireless communication with the LED light source.
 10. A LEDlighting system, comprising: a LED light source including a plurality ofcolored LEDs operable to emit one of a plurality of spectral outputs asa function of at least one current flowing through said plurality ofcolored LEDs, each current of the at least one current having a variabletime average flow; a user interface operable to facilitate a first userselection of a first spectral output from the plurality of spectraloutputs, the user interface including a touch screen operable tofacilitate the first user selection of a first color point correspondingto the first spectral output; and a controller in electricalcommunication with said user interface and said LED light source tocontrol the variable time average flow of each current flowing throughsaid plurality of colored LEDs as a function of the user selection ofthe first spectral output.
 11. The LED lighting system of claim 10,wherein the controller is in wireless communication with the LED lightsource.
 12. The LED lighting system of claim 10, wherein said userinterface is further operable to display a color temperature scaleincluding a slider bar for adjusting a color temperature of the firstspectral output.
 13. The LED lighting system of claim 10, wherein saiduser interface is further operable to display an intensity scaleencompassing a plurality of intensity levels for the first color point;and wherein said touch screen is further operable to facilitate a seconduser selection of a first intensity level for the first color point. 14.The LED lighting system of claim 13, wherein said controller is furtheroperable to scale the variable time average flow of each current as afunction of the second user selection of the first intensity level. 15.The LED lighting system of claim 10, wherein the plurality of coloredLEDs includes LEDs having at least four different colors.
 16. The LEDlighting system of claim 15, wherein the at least four colors includered, green, blue, and amber.
 17. The LED lighting system of claim 10,wherein the controller is in wireless communication with the userinterface.
 18. The LED lighting system of claim 17, wherein thecontroller is in wireless communication with the LED light source.